This invention relates to electronic devices and, more particularly, to antennas for electronic devices.
Portable computers and other electronic devices often use wireless communications circuitry. For example, wireless communications circuitry may be used to communicate with local area networks and remote base stations.
Wireless computer communications systems use antennas. It can be difficult to design antennas that perform satisfactorily in electronic devices. For example, it can be difficult to produce an antenna that performs well in noisy environments.
To enhance reliability and performance in a variety of wireless environments, some electronic devices use antenna diversity schemes. In some diversity schemes, an electronic device is provided with multiple redundant antennas each of which is located in a different portion of the device. These antennas may operate in similar radio-frequency bands and may be coupled to radio-frequency transceiver circuitry that monitors the quality of the signals that are received from the antennas in real time. If an antenna's performance drops below a given threshold, another antenna may be used for wireless communications activities. Antenna schemes of this type may offer superior performance to arrangements that rely solely on a single antenna. However, it is not always desirable to provide an electronic device with multiple antennas located in different portions of the device, as this adds wiring layout complexity and consumes valuable space within the device.
It would be desirable to be able to provide improved antenna arrangements suitable for enhancing wireless performance for an electronic device.